The present invention relates to trailer hitches, and, in particular, to a three-axis trailer hitch having an improved rotatable coupling about a longitudinal axis extending between the towing vehicle and the trailer.
Trailer hitches providing mechanical coupling about three independent axes between a towing vehicle and a trailer are known in the art. One representative example is disclosed in U.S. Pat. No. 2,133,065. The trailer hitch disclosed in this patent employs a universal joint or coupling providing limited angular movement about a first or transverse axis and about a second or vertical axis. Rotatable coupling about a third or longitudinal axis is achieved by a longitudinally extending, internally tapered socket member attached to the universal joint. The internally tapered socket member receives the forward end of an externally tapered pintle, the rear end portion of the pintle being securely connected to the trailer. The tapered forward end of the pintle is rotatably secured within the internally tapered socket member by a slidable locking pin or bolt. The trailer is disconnected from the universal joint by manually releasing the slidable locking pin and withdrawing the tapered pintle from its mating socket.
It is a principal object of the present invention to provide a strong, safe, and simple trailer hitch having improved rotational coupling about the longitudinal axis extending between the towing vehicle and the trailer.
It is another object to provide a trailer hitch having a tightly coupled rotatable joint of low friction.
An additional object is to provide a trailer hitch requiring a relatively simple adjustment to compensate for any wear of the abutting parts of the rotatable joint.
The above objects of and the brief introduction to the present invention will be more fully understood, and further objects and advantages will become apparent, from a study of the following detailed description in connection with the drawings.